Earthshine observations of an inhabited planet

TL;DR

Earthshine observations provide valuable insights into Earth's global features and their variations, serving as a proxy for studying exoplanets and detecting signs of life.

Contribution

This paper reviews recent earthshine observation techniques and results, highlighting their importance for characterizing Earth's properties and potential biosignatures.

Findings

Earthshine measurements reveal Earth's spectral and polarimetric features.

Variations in earthshine correlate with Earth's orbital and surface changes.

Earthshine studies enhance methods for exoplanet characterization.

Abstract

Earthshine is sunlight that has been reflected from the dayside Earth onto the dark side of the Moon and back again to Earth. In recent times, there has been renewed interest in ground-based visible and near-infrared measurements of earthshine as a proxy for exoplanet observations. Observations of earthshine allow us to explore and characterize the globally integrated photometric, spectral and polarimetric features of the Earth, and to extract precise information on the distinctive characteristics of our planet, and life in particular. They also allow us to quantify how this feature changes with time and orbital configuration. Here we present a brief review of the main earthshine observations and results.